import React, { useState, useMemo } from 'react'

function Test(props) {
  console.log('test更新了')
  const [msg, setMsg] = useState('hello')
  return (
    <div>
      test
      <h4>{msg}</h4>
      <h4>{props.c}</h4>
      <div>
        <button onClick={() => setMsg('hook')}>+c1</button>
      </div>
    </div>
  )
}

export default React.memo(Test)
